The present invention relates to a method of assembling a print unit for a printing machine, a method of dismantling a print unit for a printing machine, a method of transforming a print unit for a printing machine, a transport device that can be used in a method of assembling, dismantling and/or transforming a print unit, intended for a printing machine and to a device designed to be used by being inserted into a print unit intended for a printing machine. The print unit is more specifically used in a photogravure printing machine.
Photogravure is a rotary printing method that can be used for numerous media, including paper or cardboard, using engraved cylinders. Photogravure printing is particularly employed for high quality and mass circulation publications in which the graphics have to play an important role in the promotion of a product, such as packaging in the form of a cardboard box. This printing method makes it possible to print up to twelve colors or more in a single print run using solvent-based inks.
Thus, in a photogravure printing machine, a medium to be printed in the form of a continuous strip passes through a succession of photogravure print units. The print units are assembled and arranged longitudinally one after the other along a path from the entry of the medium to be printed upstream to its exit downstream. Each print unit prints a pattern with a single specific color or a particular varnish, or even performs an embossing step.
Increasingly more users want a printing machine that offers wide flexibility of use. First, they want to be able to make extremely rapid work changes by modifying the engraved printing cylinders, in order to meet their customers' increasingly customized demands for short print runs. Then, a need emerged in terms of additional visual effects to be reproduced on the medium, such as gilding and silvering, matt, shiny or structured varnishes, recto, verso, embossings and other visual effects, also requiring new printing techniques. However, because of the length of the printing machines and because of the very high costs, users can rarely add additional print units in the middle of a printing machine.